We introduce the concept of a sympathetic
interface for controlling an animated synthetic character in a 3D
virtual environment. A plush doll embedded with wireless sensors is
used to manipulate the virtual character in an iconic and
intentional manner. The interface extends from the novel physical
input device through interpretation of sensor data to the behavioral
brain of the virtual character. We discuss the design of the
interface and focus on its latest instantiation in the Swamped!
exhibit at SIGGRAPH 98. We also present what we learned from
hundreds of casual users, who ranged from young children to adults.